improve inventory of hardware resources

Description

We currently have a few hosting providers and locations where we have "stuff":

virtual machines

colocated servers

raspberri pi under desk

routers

"cloud" things (like AWS)

test machines

etc

TPO machines are currently documented in LDAP. But they are also in Puppet. And there's a spreadsheet (which we want to replace with something else, probably a grafana dashboard, in #29816). And there are many things (like AWS) which are not really tracked formally anywhere that I am aware of.

So this project is about establishing a clearer process to keep such an inventory. It should at least cover the following, TPO-managed infrastructure:

physical servers

virtual machines on those physical servers *or* on other cloud providers

Ideally, we would also have a unified view of this for all machines paid for by TPI, regardless of the team.

The last bit is of course related to another problem, which is lifecycle management (see parent ticket #29304).

A lot of that stuff is currently in LDAP and maybe it should just be added there. But I wonder if it would be useful to create another system (which might eventually supersede LDAP) that would be more flexible. If that process would happen at all, we would first need to thoroughly document how hosts are integrated into LDAP and so on, of course.